The invention relates to flow control in a wellbore.
In completing a well, one or more zones in one or more formations may be perforated to enable production of hydrocarbons. Completion equipment including tubing, packers, flow control devices, and other devices may be installed in various positions in the well to manage the production from respective zones. Flow control devices may include valves such as sleeve valves, disk valves, ball valves, flapper valves, and other types of valves. A sleeve valve typically includes a sliding sleeve that extends around the full circumference of a tubing or pipe having one or more flow orifices. The sliding sleeve is movable with respect to the flow orifices to provide flow control. Elastomeric seals are used to provide the desired sealing when the sliding sleeve is in the closed position. Another type of valve is the disk valve, which includes a cover that is slidable with respect to a seat defining an orifice. The peripheries of the cover and seat provide the desired sealing. The cover and seat may be formed of or coated with a material having a low coefficient of friction to facilitate sliding movement between the cover and seat to open and close the disk valve.
One of the concerns associated with flow control devices is the flow area that such flow control devices provide. For example, the orifice or orifices that a sleeve valve or disk valve controls may have a flow area that is smaller than the flow area of a tubing or pipe used to carry the fluid to the surface. As a result, "full bore flow" may not be achieved by the valve, which may have the effect of limiting fluid flow rate during production.
Thus, a method and apparatus is needed to increase flow areas provided by flow control devices.